Summary. We evaluated the efficacy and toxicity of fludarabine combined with cyclophosphamide and mitoxantrone (FCM) in patients with relapsed or resistant chronic lymphocytic leukaemia (CLL). In total, 37 patients with recurrent or resistant CLL received FCM: fludarabine 25 mg/m2 intravenously (IV), d 1–3; cyclophosphamide 200 mg/m2 IV, d 1–3; and mitoxantrone 6 mg/m2 IV, d 1, at 4‐week intervals for up to six courses. Moreover, 23 patients received FCM with cyclophosphamide 600 mg/m2 i.v. and mitoxantrone 8 mg/m2 i.v. on d 1. In addition to clinical methods, response was assessed using cytofluorometric and molecular techniques. ‘In vitro’ sensitivity to the FCM regimen was also analysed in 20 samples. The median number of courses given was 3 (range: 1–6). Overall, 30 patients (50%) achieved complete response (CR), including 10 cases of negative minimal residual disease (MRD(–)) (17%), and 17 (28%) partial response (PR). The median duration of response was 19 months. ‘In vitro’ sensitivity also correlated with CR achievement (P = 0·04). Main toxicity consisted of neutropenia, infections (8% of courses), and nausea and vomiting. The treatment‐related mortality was 5%. FCM did not hamper stem cell harvesting in patients who were candidates for autologous stem cell transplantation. FCM induced a high CR rate, including an important number of MRD(–), in patients with previously treated CLL.

To contribute to a better knowledge of the prognosis of idiopathic myelofibrosis (IM), the prognostic value of the presenting features in 106 patients diagnosed with IM at a single institution during a 21‐year period was retrospectively analysed. Median survival was 59.4 months (95% CI 40.7–75.4). Using univariate analysis, age < 64 years, constitutional symptoms (fever, night sweats, weight loss), Hb < 10 g/dl, circulating blasts (≫1%), and serum LDH > 3 times upper normal level were associated with a significantly shorter survival; male sex, platelet count <100×109/l, blood percentage of immature granulocytes (excluding blasts), low cholesterol levels and advanced marrow histological stage had borderline significance. Using multivariate study, only age > 64 years, constitutional symptoms, Hb < 10 g/dl, and circulating blasts retained their prognostic relevance. The latter three variables confirmed their predictive value in patients above and below the series median age, and were able to identify two groups of patients: a low‐risk group of 67 patients with none or one bad prognostic factor, in whom IM had an indolent course (median survival 98.8 months, 95% CI 68.7–127.6), and a high‐risk group, including 39 patients with two or three factors, with a more aggressive disease (median survival 20.6 months, 95% CI 10–28.2). Finally, the application of two recently proposed scoring systems (in which three prognostic groups are considered) was unable to separate intermediate‐ from high‐risk patients.

The molecular mechanisms underlying the pathogenesis of aggressive lymphomas and the histological transformation of indolent variants are not well known. To determine the role of p16INK4a gene alterations in the pathogenesis of non-Hodgkin's lymphomas (NHLs) and the histological progression of indolent variants, we have analyzed the expression, deletions, and mutations of this gene in a series of 112 NHLs. Hypermethylation of the gene was also examined in a subset of tumors with lack of protein expression but without mutations or deletions of the gene. p16INK4a gene alterations were detected in 3 out of 64 (5%) indolent lymphomas but in 16 out of 48 (33%) primary or transformed aggressive variants. In the low-grade tumors, p16INK4a alterations were detected in 1 (4%) chronic lymphocytic leukemia (hemizygous missense mutation), 1 (6%) follicular lymphoma (homozygous deletion), and 1 (5%) typical mantle cell lymphoma (homozygous deletion). The two later cases followed an aggressive clinical evolution. In the aggressive tumors, p16INK4a gene alterations were observed in 2 (29%) Richter's syndromes (2 homozygous deletions), 3 (33%) transformed follicular lymphomas (1 homozygous deletion and 2 nonsense mutations), 3 (43%) blastoid mantle cell lymphomas (2 homozygous and 1 hemizygous deletions), 5 (28%) de novo large-cell lymphomas (1 homozygous deletion and 4 hypermethylations), 2 lymphoblastic lymphomas (2 homozygous deletions), and 1 of 2 anaplastic large cell lymphomas (hypermethylation). Protein expression was lost in all tumors with p16INK4a alterations except in the typical chronic lymphocytic leukemia (CLL) with hemizygous point mutation. Sequential samples of the indolent and transformed phase of three cases showed the presence of p16INK4a deletions in the Richter's syndrome but not in the CLL component of two cases, whereas in a follicular lymphoma the deletion was present in both the follicular tumor and in the diffuse large-cell lymphoma. In conclusion, these findings indicate that p16INK4a gene alterations are a relatively infrequent phenomenon in NHLs. However, deletions, mutations, and hypermethylation of the gene with loss of protein expression are associated with aggressive tumors and they may also participate in the histological progression of indolent lymphomas.

INK4a/ARF locus codes for two different proteins, p16(INK4a) and p14(ARF), involved in cell cycle regulation. p14(ARF) is considered an upstream regulator of p53 function. To determine the role of these genes in the pathogenesis of human non-Hodgkin's lymphomas we have analyzed exon 1beta, 1alpha, and 2 of the INK4a/ARF locus and p53 gene aberrations in 97 tumors previously characterized for p16(INK4a) alterations. p53 alterations were detected in four of 51 (8%) indolent lymphomas but in 15 of 46 (33%) aggressive tumors. Inactivation of p14(ARF) was always associated with p16(INK4a) alterations. Exon 1beta was concomitantly deleted with exon 1alpha and 2 in eight tumors. One additional lymphoblastic lymphoma showed deletion of exon 1alpha and 2 but retained exon 1beta. No mutations were detected in exon 1alpha and 1beta in any case. Two of the three mutations detected in exon 2 caused a nonsense mutation in the p16(INK4a) reading frame and a missense mutation in the ARF reading frame involving the nucleolar transport domain of the protein. The third mutation was a missense mutation in the p16(INK4a) reading frame, but it was outside the coding region of p14(ARF). Aggressive lymphomas with p14(ARF) inactivation and p53 wild type showed a significantly lower p53 protein expression than tumors with no alteration in any of these genes. In this series of tumors, inactivation of the INK4a/ARF locus mainly occurred in tumors with a wild-type p53 gene because only two lymphomas showed simultaneous aberrations in these genes. Tumors with concomitant alterations of p16(INK4a) and p14(ARF)/p53 genes seem to exhibit a worse clinical behavior than lymphomas with no alterations or isolated inactivation of any of these genes. These findings indicate that p14(ARF) genetic alterations occur in a subset of aggressive NHLs, but they are always associated with p16(INK4a) aberrations. Concomitant disruption of p16(INK4a) and p14(ARF)/p53 regulatory pathways may have a cooperative effect in the progression of these tumors.

Summary. Thalidomide is active in patients with refractory myeloma. Seventeen patients (nine men/eight women, median age 73 years) with multiple myeloma (MM) were treated with thalidomide. Fifteen patients had refractory disease and two untested relapse. The median dose of thalidomide was 500 mg (range, 200±800 mg). Nine of the 17 patients (53%) responded. The response rate was significantly higher in patients with no extramedullary disease than in those with soft tissue masses (75% CI: 43±95% versus 0%; P 0´01)). Of note, no decrease in the size of soft tissue plasmacytomas was observed in all the five patients who had extramedullary involvement. This data suggests that the mechanism of action and effectiveness of thalidomide might depend on the site of the tumour cells.